1. Field of the Invention
The present invention relates to a ferroelectric recording medium, a recording apparatus comprising the same, and a recording method of the same, and more particularly, to a ferroelectric recording medium comprising an anisotropic conduction layer and a recording method of the same.
2. Description of the Related Art
In general a ferroelectric material has spontaneous polarization, which is reversed by an electric field. A ferroelectric recording medium is a nonvolatile recording medium having a high capacity on which data is recorded, corrected, and stored by using such a property of ferroelectric materials.
Japanese Laid-open Patent No. 2002-175602 discloses an example of a conventional ferroelectric recording medium, which is illustrated in FIG. 1.
Referring to FIG. 1, a ferroelectric recording layer 2 and a reading/writing head tip 1 are in direct contact in a conventional ferroelectric recording medium, and thus both the ferroelectric recording layer 2 and the reading/writing head tip 1 may be damaged. More specifically, the ferroelectric recording layer 2 and the reading/writing head tip 1 are formed of hard materials, and thus the damage may be serious. In other words, scratches may be formed on the ferroelectric recording layer 2, resulting in the deterioration of the stability of data recorded on the ferroelectric recording layer 2. In addition, the reading/writing head tip 1 may be damaged, resulting in the deterioration of reading/writing performance.
In order to prevent such problems, a soft protective film 3 covers the ferroelectric recording layer 2, as shown in FIG. 2. The soft protective film 3 prevents direct contact between the ferroelectric recording layer 2 and the reading/writing head tip 1 during a reading/writing operation, and thus the damage of the ferroelectric recording layer 2 and the reading/writing head tip 1 are prevented.
However, the protective film 3 on the ferroelectric recording layer 2 has low permittivity, and thus a voltage applied by the head tip 1 to the protective film 3 is distributed through the protective film 3. As a result, a high voltage is required for a writing operation. More specifically, permittivity determines a ratio between an electric flux density and an electric field, and since the permittivity of the protective film 3 is very low, the protective film 3 has a high resistance. Accordingly, when a writing operation is performed on the ferroelectric recording layer 2, a large applied voltage is distributed to the protective film 3 according to the ratio of the resistance of the protective film 3 and the ferroelectric recording layer 2. Thus, a high voltage is required to perform a writing operation on the ferroelectric recording layer 2, considering a voltage distribution ratio of the protective film 3 and the ferroelectric recording layer 2.